Paul Wellstone Mental Health Equitable Treatment Act of 2005 - Amends the Employee Retirement Income Security Act of 1974 (ERISA) and the Public Health Service Act to prohibit a group health plan or group health coverage that provides both medical and surgical benefits and mental health benefits from imposing treatment limitations or financial requirements on the mental health benefits unless comparable limitations or requirements are imposed on medical and surgical benefits. Excludes such requirements for plans and coverage for small employers.
Allows a plan or coverage that provides in-network mental health benefits to provide out-of-network mental health benefits using treatment limitations or financial requirements that are not comparable to those applied to medical-surgical benefits if the in-network mental health benefits are provided at parity with medical-surgical benefits and with reasonable access.
Requires the Government Accountability Office (GAO) to: (1) study the effects of this Act on health insurance costs and access and quality of health care; and (2) provide a cost estimation of extending such requirements to the treatment of substance abuse and chemical dependency.